A top cover of a containment vessel and a nuclear power plant containment vessel

Abstract

The application discloses a top cover of a nuclear power plant safety shell, which has a curved surface structure and comprises an inner shell and an outer shell, wherein the inner shell and the outer shell are arranged at intervals, the outer shell is located at the radial outer side of the inner shell, a hollow part is formed between the inner shell and the outer shell, and the hollow part is filled with a non-Newtonian fluid, so that the impact resistance and the shock resistance of the safety shell are improved.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant containment technology, and more specifically, to a top cover of a containment vessel and a nuclear power plant containment vessel. Background Technology

[0002] In recent years, with the advancement of science and technology and economic development, human society's demand for energy has been continuously rising, while simultaneously placing increasing emphasis on the protection of the ecological environment. Nuclear energy, as a highly efficient and clean energy source, has become one of the more ideal energy forms worldwide and is used by many countries. However, nuclear safety issues have become a factor restricting the development of nuclear power in many countries and regions, with several historical nuclear accidents bringing devastating consequences. Therefore, focusing on the safety of nuclear power plants is a prerequisite for the development of nuclear energy. The containment vessel, as the fourth barrier of a nuclear power plant, plays an extremely important role. On the one hand, it needs to resist external loads and forces, such as large aircraft impacts and earthquakes, to prevent damage to the reactor inside; on the other hand, it needs to withstand the pressure from inside the vessel after an accident and ensure the structural seal to prevent the leakage of radioactive materials. Therefore, innovation in the containment vessel structure is necessary to improve the safety of nuclear energy use.

[0003] Current containment structures still have certain shortcomings. For example, many containment structural designs aim to improve safety by increasing the number of structural layers. However, because the containment itself is large, increasing the number of layers further increases the space occupied by the containment, as well as the amount of materials used and the cost. At the same time, increasing the number of containment layers means that a large amount of construction work needs to be carried out at heights, which will increase the difficulty of construction and the construction period, thus having a significant negative impact on the economics of nuclear power plant construction.

[0004] Furthermore, with the deepening research in the field of vibration control of civil structures, many dampers suitable for civil building structures have been developed. However, the application of various dampers is still relatively rare in industrial buildings such as nuclear power plants, which have high requirements for vibration control. In addition, in traditional containment design, seismic action and aircraft impact are considered separately and resisted by different design measures. This increases the complexity of the containment structure and the corresponding components cannot be fully utilized.

[0005] Patent CN112863707A discloses a sandwich-type containment structure suitable for severe safety accidents, comprising an outer shell layer, an intermediate layer, and an inner shell layer nested sequentially. The outer shell layer is a thickened steel plate, while the intermediate and inner shell layers are composed of prestressed concrete layers and steel linings on their inner and outer sides. A sealed intermediate containment space is formed between the inner shell layer and the intermediate layer, and a sealed outermost containment space is formed between the intermediate layer and the outer shell layer. The inner shell layer is connected to the ground via multiple seismic isolation bearings arranged in a checkerboard pattern. The intermediate layer is connected to the ground via multiple evenly distributed rocker bearings, and multiple rows of circumferential viscoelastic dampers with granules are installed in the outermost space. This technical solution has a large number of containment layers, occupies a large structural area, and has complex design and installation of various bearings and dampers, resulting in low utilization.

[0006] Patent CN108877963A discloses a double-layer containment structure that achieves technical isolation of horizontal earthquakes by a base isolation-tuned mass damping (BIS-TMD) seismic isolation and damping structure, and adds an anti-impact structure, but it is fundamentally different from the design of the vibration isolation and damping structure and damper in this application.

[0007] In view of the above technical problems, this invention is hereby introduced. Summary of the Invention

[0008] The main objective of this invention is to provide a top cover for a containment structure and a containment structure for nuclear power plants, which simplifies the containment structure and improves the containment's resistance to earthquakes and impacts.

[0009] To achieve the above objectives, according to one aspect of the present invention, a top cover for a nuclear power plant containment vessel is provided, having a curved structure, further comprising an inner shell and an outer shell, the inner shell and the outer shell being spaced apart, the outer shell being located radially outside the inner shell, and a hollow portion being formed between the inner shell and the outer shell, the hollow portion being filled with a non-Newtonian fluid to improve the containment vessel's impact and seismic resistance.

[0010] Furthermore, the top cover also includes multiple partitions located inside the hollow section. The two sides of the partitions are connected to the inner shell and the outer shell, respectively, and the multiple partitions divide the hollow section into multiple spaces.

[0011] Furthermore, multiple baffles are spaced apart along the height direction, dividing the space inside the hollow section into 3-5 layers of fluid space along the height direction. Each layer of fluid space contains non-Newtonian fluid, so that the vibration frequency of the non-Newtonian fluid in the hollow section is close to the natural frequency of the containment.

[0012] Furthermore, non-Newtonian fluids are shear-thickening fluids, and the critical shear wave velocity of non-Newtonian fluids is in the range of 10 m / s to 100 m / s.

[0013] Furthermore, the shear thickening fluid includes polyethylene glycol and silica, with the silica mass fraction ranging from 60% to 65%.

[0014] Furthermore, both the inner and outer shells have spherical structures, and at least one partition has an annular structure, which surrounds the outer circumference of the inner shell, dividing the hollow portion into upper and lower parts.

[0015] Furthermore, the partition includes a first partition, a second partition, and a third partition. The first partition, the second partition, and the third partition have an annular structure and are arranged sequentially from high to low along the height direction, dividing the hollow part into three layers of fluid space.

[0016] Furthermore, the surfaces of multiple partitions, the outer wall of the inner shell, and the inner wall of the outer shell are all covered with anti-corrosion materials.

[0017] Furthermore, the top cover also includes an inner top layer, which comprises a prestressed concrete shell located radially inside the inner shell.

[0018] By applying the above-described top cover technical solution of the present invention, at least the following beneficial effects are achieved:

[0019] 1. The top cover of this application has a two-shell structure with an inner shell and an outer shell on the outside, which serves as the first line of defense against the impact of large objects. The space in the hollow part provides space for the deformation of the outer shell, so that when the outer shell is deformed by impact, the inner shell and the prestressed concrete shell are not damaged. Multiple partitions are set in the hollow part at intervals to enhance the overall strength of the two-shell structure and to constrain the deformation range of the outer shell.

[0020] 2. The top cover of this application uses a non-Newtonian fluid as a filler in the two-layer shell structure, which significantly improves the ability of the top of the containment to buffer the impact of large objects and reduces the possibility of secondary disasters caused by the impact. When a large object impacts, the non-Newtonian fluid can share the impact force with the two-layer shell structure, reduce the deformation range of the shell, and evenly distribute the impact force. At the same time, the impact can easily cause a fire. The non-Newtonian fluid inside the two-layer shell structure can reduce the temperature of the shell and has strong fire resistance to prevent the top cover structure of the containment from failing.

[0021] 3. The top cover of this application designs the structure of the fluid space inside the hollow part, and designs the material and parameters of the non-Newtonian fluid inside the fluid space, so that the non-Newtonian fluid inside the top cover forms a tuned liquid damper, which greatly improves the seismic performance of the containment. Under strong vibrations such as earthquakes, the inertia of the liquid itself is used to reduce the horizontal vibration of the upper part of the containment.

[0022] 4. The top cover of this application, by setting anti-corrosion materials on the surfaces of the inner and outer shells, achieves a better sealing effect for the non-Newtonian fluid inside the two shell structures, preventing the non-Newtonian fluid from seeping into the concrete; in addition, when the pressure inside the containment increases sharply, the non-Newtonian fluid itself can act as a counterweight to prevent the top cover of the containment from being ruptured by the internal pressure.

[0023] To achieve the above objectives, according to another aspect of the present invention, a nuclear power plant containment vessel is provided, comprising a sidewall and a top cover, the sidewall being located below and connected to the top cover, the sidewall comprising a plurality of annular beams and a plurality of viscous dampers, the annular beams surrounding the containment vessel in a circumferential direction, the plurality of annular beams being spaced apart in a height direction, and the plurality of viscous dampers being distributed between the plurality of annular beams.

[0024] Furthermore, the upper end of the viscous damper is connected to the lower edge of the annular beam above it, and the lower end of the viscous damper is connected to the upper edge of the annular beam below it.

[0025] Furthermore, the lower edge includes a first fixing point, and the upper edge includes a second fixing point. The first fixing point is located radially inside the containment relative to the second fixing point. The upper end of the viscous damper is fixed to the first fixing point, and the lower end of the viscous damper is fixed to the second fixing point, so that the viscous damper is tilted.

[0026] Furthermore, the viscous material of the viscous damper includes silicone oil, the damping coefficient of the viscous damper is in the range of 0.12-0.18, and the maximum output force is in the range of 1000-2000kN.

[0027] Furthermore, between every two adjacent annular beams, multiple viscous dampers are evenly spaced along the circumference of the containment.

[0028] Furthermore, the sidewall also includes an inner wall layer and multiple buttress columns. The inner wall layer includes a cylindrical prestressed concrete inner wall, with a ring beam surrounding the outer side of the prestressed concrete inner wall in the circumferential direction. The buttress columns extend in the height direction and connect multiple ring beams. The multiple buttress columns are evenly arranged along the outer circumferential direction of the prestressed concrete inner wall.

[0029] Furthermore, multiple viscous dampers and multiple buttress columns are arranged alternately and at intervals along the circumferential outer side of the prestressed concrete inner wall.

[0030] Furthermore, the containment also includes a base plate and a support assembly. The base plate is located at the bottom of the sidewalls, and the support assembly connects the base plate to the ground to support the containment. The support assembly includes multiple friction dampers.

[0031] Furthermore, multiple friction dampers are arranged radially outward from the center of the base plate.

[0032] Furthermore, the friction damper includes a laminated steel plate and friction-type high-strength bolts, which fix the laminated steel plate. The surface friction coefficient of the laminated steel plate is in the range of 0.4-0.6.

[0033] Furthermore, multiple friction dampers are arranged in multiple directions with central angles of 15 to 45 degrees, and the number of friction dampers in each direction is no less than three.

[0034] Furthermore, the support assembly also includes multiple vibration isolation supports, which are installed below the edge of the base plate and / or at the bottom of the buttress column.

[0035] Furthermore, the base plate includes a prestressed concrete base plate, and the prestressed concrete base plate, the prestressed concrete inner wall, and the prestressed concrete shell are continuous to form the prestressed concrete inner layer of the containment structure.

[0036] Furthermore, a steel lining is also provided on the inner side of the prestressed concrete inner layer.

[0037] Furthermore, the containment also includes multiple supports, which are fixed to the foundation and circumferentially surround the perimeter of the sidewalls.

[0038] Furthermore, a limiting part is provided on the side of the support near the side wall. The limiting part includes a viscoelastic material, so that multiple supports can make flexible contact when they collide with the side wall.

[0039] Furthermore, the limiting parts of the multiple supports are respectively located on the radial outer side of the multiple buttresses in the circumferential direction, and the limiting parts at the same radial position are in clearance fit with the buttress column.

[0040] By applying the above-described containment technology of the present invention, at least the following beneficial effects are achieved:

[0041] 1. The containment structure of this application increases the circumferential constraint of the containment structure and enhances its ability to resist internal pressure by setting multiple annular beams on the outer side of the sidewalls; by setting multiple buttresses to bear the weight of the upper two shell structures and non-Newtonian fluids, and connecting the multiple annular beams, the annular beams and buttresses divide the sidewalls of the containment structure into several small grids. When a large object impacts the sidewalls of the containment structure, the annular beams and buttresses can constrain the fracture deformation within the impacted grids to reduce the overall damage to the containment structure and avoid progressive collapse.

[0042] 2. The containment structure of this application can reduce the bending and shear deformation of the containment structure under impact or vibration by consuming energy through multiple viscous dampers arranged on the side wall of the containment structure. The inclined arrangement of the viscous dampers can increase energy consumption in both the vertical and radial directions of the containment structure at the same time, thereby reducing the impact of structural deformation on the internal pipes and valves of the containment structure and preventing the containment structure from cracking and causing the leakage of radioactive materials.

[0043] 3. The containment structure of this application arranges the friction dampers under the bottom plate in a radial pattern, which not only makes the energy dissipation capacity of the containment structure similar in all directions, but also ensures that the natural vibration period of the containment structure is similar in all directions. This allows the tuned mass damper formed by the non-Newtonian fluid in the top cover to play a damping effect in all directions, thereby avoiding the concentration of vibration damage on one side of the containment structure. In addition, the containment structure is provided with seismic isolation bearings around the bottom, which allows the natural vibration period of the containment structure to avoid the natural period of the site, thereby reducing resonance.

[0044] 4. This application sets up multiple supports around the main structure of the containment vessel. When vibration causes a large lateral displacement at the bottom of the containment vessel, the reinforced concrete supports around the containment vessel serve as the main components for transmitting lateral forces and resisting lateral displacement. This can effectively limit the horizontal lateral displacement of the containment vessel in all directions. Compared with a multi-layer containment vessel structure, the supports have the advantages of low height, easy construction, and short force transmission path.

[0045] 5. This application achieves phased energy dissipation by setting a viscoelastic limiting part on the side of the support near the sidewall, which, in combination with the friction damper at the bottom, can dissipate energy in stages. When the displacement response at the bottom of the containment is small, the friction damper is mainly used to dissipate energy. When the displacement response at the bottom of the containment is large enough, energy can be dissipated through both the collision limiting part and the friction damper. The support ensures that the displacement at the bottom of the containment does not exceed a certain limit, and at the same time plays the role of transmitting horizontal loads, seismic forces and resisting overturning moments. After the limiting part collides with the sidewall, the containment can automatically reset, which is beneficial for structural repair and maintenance after a disaster and reduces the amount of repair work. Attached Figure Description

[0046] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0047] Figure 1 A schematic cross-sectional view of the containment structure according to one embodiment is shown;

[0048] Figure 2 A front view of the enclosure exterior of one embodiment is shown;

[0049] Figure 3 A schematic diagram of the installation of a viscous damper according to one embodiment is shown;

[0050] Figure 4 A top sectional view of the containment structure of one embodiment is shown;

[0051] Figure 5A schematic diagram of a friction damper arrangement according to one embodiment is shown.

[0052] The above figures include the following reference numerals:

[0053] 1. Inner shell; 2. Outer shell; 3. Partition; 4. Fluid space; 5. First partition; 6. Second partition; 7. Third partition; 8. Prestressed concrete shell; 9. Circular beam; 10. Viscous damper; 11. First fixed point; 12. Second fixed point; 13. Buttress column; 14. Prestressed concrete inner wall; 15. Friction damper; 16. Vibration isolation support; 17. Prestressed concrete base plate; 18. Steel lining; 19. Support body; 20. Limiting part. Detailed Implementation

[0054] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0055] The present invention will be further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed by the present invention. The term "comprising" indicates the presence of a feature, but does not exclude the presence or addition of one or more other features. The terms "lateral," "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the purpose of description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0056] In this description, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0057] Example:

[0058] like Figure 1 and Figure 2As shown, this application proposes a top cover for a nuclear power plant containment vessel, located at the top of the containment vessel, and having a curved structure. In practical applications, this top cover is not limited to being part or all of a component such as a containment head or dome. Preferably, in this embodiment, the top cover is a dome of the containment vessel, and the dome has a spherical structure.

[0059] The top cover includes an inner shell 1 and an outer shell 2, which are spaced apart, with the outer shell 2 located radially outside the inner shell 1. A hollow section is formed between the inner shell 1 and the outer shell 2, and the hollow section is filled with a non-Newtonian fluid to improve the impact and seismic resistance of the containment.

[0060] In addition, the top cover also includes an inner top layer located radially inside the two-shell structure. The inner top layer includes a prestressed concrete shell 8, which is located radially inside the inner shell 1. The inner shell 1 is attached to the outside of the prestressed concrete shell 8. A steel liner 18 is also located radially inside the prestressed concrete shell 8. The steel liner 18 and the prestressed concrete shell 8 are used to withstand the internal pressure of the containment vessel under severe accidents and to prevent the leakage of radioactive materials.

[0061] The top cover of this application has a two-shell structure with an inner shell and an outer shell on the outside, which serves as the first line of defense against the impact of large objects. The hollow space provides space for the deformation of the outer shell, so that when the outer shell is deformed by impact, the inner shell and the prestressed concrete shell are not damaged. Multiple partitions are set in the hollow space to enhance the overall strength of the two-shell structure and to constrain the deformation range of the outer shell.

[0062] The top cover of this application uses a non-Newtonian fluid as a filler in the two-layer shell structure, which significantly improves the ability of the containment top to buffer the impact of large objects and reduces the possibility of secondary disasters caused by the impact. When a large object impacts, the non-Newtonian fluid can share the impact force with the two-layer shell structure, reduce the deformation range of the shell, and evenly distribute the impact force. At the same time, the impact can easily cause a fire. The non-Newtonian fluid inside the two-layer shell structure can reduce the temperature of the shell and has strong fire resistance to prevent the failure of the containment top cover structure.

[0063] The top cover also includes multiple partitions 3 located within the hollow section. The two sides of each partition 3 are connected to the inner shell 1 and the outer shell 2, respectively. The multiple partitions 3 divide the hollow section into multiple spaces. The multiple partitions can be connected to each other or arranged at intervals to divide the space of the hollow section into multiple interconnected or non-interconnected parts.

[0064] Preferably, multiple partitions 3 are spaced apart along the height direction, dividing the space inside the hollow section into 3-5 layers of fluid space 4 along the height direction, each layer of fluid space 4 containing non-Newtonian fluid. By controlling parameters such as the volume of non-Newtonian fluid in each layer of fluid space 4, the vibration frequency of the non-Newtonian fluid in the hollow section is made close to the natural frequency of the containment vessel.

[0065] Specifically, preferably, both the inner shell 1 and the outer shell 2 have a hemispherical structure, and at least one partition 3 has an annular structure. The partition 3 surrounds the outer circumference of the inner shell 1, dividing the hollow part into upper and lower parts.

[0066] More preferably, such as Figure 1 As shown, the partition 3 includes a first partition 5, a second partition 6, and a third partition 7. These partitions have annular structures and are arranged sequentially from high to low along the height direction, dividing the hollow portion into three fluid spaces 4. The surface of the first partition 5 extends radially along the hemispherical structure, with its extension direction forming a 60-degree angle with the horizontal plane. The surface of the second partition 6 extends radially along the hemispherical structure, with its extension direction forming a 30-degree angle with the horizontal plane. The surface of the third partition 7 is parallel to the horizontal plane and located at the bottom of the top cover, sealing and isolating the hollow portion from below. Thus, the hollow portion of the two-layer shell structure formed by the inner shell 1 and the outer shell 2 is divided into three independent fluid spaces 4, with the lower two fluid spaces being annular spaces.

[0067] Preferably, the inner shell, outer shell, and partition can be made of steel. Depending on the height of the three-layer fluid space 4, holes can be pre-reserved on the outer shell 2 for injecting non-Newtonian fluid. After the non-Newtonian fluid is injected, the holes are covered by welding with steel plates.

[0068] Preferably, the non-Newtonian fluid is a shear-thickening fluid, and the critical shear wave velocity of the non-Newtonian fluid is in the range of 10 m / s to 100 m / s. The shear-thickening fluid includes polyethylene glycol and silica, with the mass fraction of silica in the range of 60% to 65%. This allows the non-Newtonian fluid to dissipate energy during sloshing and increases its shear strength under high-speed impact.

[0069] The top cover of this application designs the structure of the fluid space inside the hollow section, and designs the material and parameters of the non-Newtonian fluid inside the fluid space, so that the non-Newtonian fluid inside the top cover forms a tuned liquid damper, which greatly improves the seismic performance of the containment. Under strong vibrations such as earthquakes, the inertia of the liquid itself is used to reduce the horizontal vibration of the upper part of the containment.

[0070] Preferably, the surfaces of the multiple partitions 3, the outer wall of the inner shell 1, and the inner wall of the outer shell 2 are all covered with anti-corrosion materials, and the two sides of the partitions 3 are respectively welded to the inner shell 1 and the outer shell 2. These designs provide a better sealing effect for non-Newtonian fluids inside the two-shell structure, ensuring watertightness and preventing non-Newtonian fluids from seeping into the concrete.

[0071] In addition, when the pressure inside the containment increases dramatically, the non-Newtonian fluid itself can act as a counterweight to prevent the top cover of the containment from being ruptured by the internal pressure.

[0072] like Figure 1 and Figure 2 As shown, this application also proposes a structure for a nuclear power plant containment vessel, including a sidewall and the aforementioned top cover. The sidewall is located below the top cover and connected to it. The sidewall includes a plurality of annular beams 9 and a plurality of viscous dampers 10. The annular beams 9 surround the containment vessel in the circumferential direction, and the plurality of annular beams 9 are arranged at intervals in the height direction. The plurality of viscous dampers 10 are distributed between the plurality of annular beams 9.

[0073] The sidewall also includes an inner wall layer and multiple buttress columns 13. The inner wall layer includes a cylindrical prestressed concrete inner wall 14, with annular beams 9 surrounding the outer side of the prestressed concrete inner wall 14 in the circumferential direction. The buttress columns 13 extend along the height direction and connect to the multiple annular beams 9, and the multiple buttress columns 13 are evenly arranged outwards around the prestressed concrete inner wall 14. The prestressed concrete inner wall 14 is continuous with the prestressed concrete shell 8 of the top cover. The annular beams 9 and buttress columns 13 are all located outside the prestressed concrete inner wall 14 to support the weight of the two-layer shell structure of the top cover.

[0074] Preferably, the materials for the annular beams 9 and the buttress columns 13 are also prestressed concrete. In this embodiment, four prestressed concrete annular beams 9 are provided, evenly arranged along the height. The first annular beam 9 from top to bottom is close to the lower edge of the double-layered spherical shell, and the fourth annular beam is flush with the bottom plate of the containment vessel. At the same time, four concrete buttress columns 13 are evenly arranged on the outer side of the prestressed concrete inner wall 14, evenly spaced at 90-degree intervals around the circumference.

[0075] The containment structure of this application increases the circumferential constraint of the containment structure by setting multiple annular beams on the outer side of the sidewalls, thereby enhancing the containment structure's ability to resist internal pressure. By setting multiple buttress columns to bear the weight of the two upper shell structures and the non-Newtonian fluid, and connecting the multiple annular beams, the annular beams and buttress columns divide the sidewalls of the containment structure into several small grids. When a large object impacts the sidewalls of the containment structure, the annular beams and buttress columns can constrain the fracture deformation within the impacted grid, thereby reducing the overall damage to the containment structure and preventing progressive collapse.

[0076] like Figure 2 and Figure 3As shown, the upper end of the viscous damper 10 is connected to the lower edge of the annular beam 9 located above it, and the lower end of the viscous damper 10 is connected to the upper edge of the annular beam 9 located below it.

[0077] Specifically, the lower edge includes a first fixing point 11, and the upper edge includes a second fixing point 12. The first fixing point 11 is located radially inward of the containment relative to the second fixing point 12. The upper end of the viscous damper 10 is fixed to the first fixing point 11, and the lower end of the viscous damper 10 is fixed to the second fixing point 12, thus the viscous damper 10 is inclined. By inclinedly setting multiple viscous dampers 10 between the annular beams, energy dissipation can be increased in both the vertical and radial directions of the containment, reducing the seismic impact effect and effectively suppressing structural deformation.

[0078] Preferably, the upper end of the viscous damper 10 is fixed to the inner edge of the ring beam 9, and the lower end of the viscous damper 10 is fixed to the outer edge of the ring beam 9. Hinge supports are formed at both ends of the viscous damper by fixing it with ear plates and bolts embedded in the prestressed concrete ring beam 9.

[0079] Preferably, the viscous material of the viscous damper 10 includes silicone oil. The silicone oil chosen as the fluid is not easily affected by temperature, ensuring the stability of the viscous damper 10 at high temperatures. Furthermore, the damping coefficient of the viscous damper 10 is in the range of 0.12-0.18, preferably around 0.15. A smaller damping coefficient allows the viscous damper to dissipate energy more easily in containment structures subjected to earthquakes and impacts. The maximum output force of the viscous damper 10 is in the range of 1000-2000 kN; a larger output force can suppress deformation caused by vibration.

[0080] Preferably, combined with Figure 2 and Figure 4 As shown, between every two adjacent annular beams 9, a plurality of viscous dampers 10 are evenly spaced along the circumference of the containment. The plurality of viscous dampers 10 and the plurality of buttress columns 13 are alternately spaced along the circumference of the prestressed concrete inner wall 14. More preferably, the plurality of viscous dampers 10 and the plurality of buttress columns 13 are arranged at 45-degree intervals around the circumference.

[0081] The containment structure of this application, through multiple viscous dampers arranged on the sidewalls of the containment, can reduce the bending and shear deformation of the containment structure under impact or vibration by dissipating energy, thereby reducing the impact of structural deformation on the internal pipes and valves of the containment and preventing the containment from cracking and causing leakage of radioactive materials.

[0082] like Figure 1 As shown, the containment also includes a base plate and a support assembly. The base plate is located at the bottom of the sidewall, and the support assembly connects the base plate to the ground to support the containment. The support assembly includes a plurality of friction dampers 15.

[0083] like Figure 5 As shown, multiple friction dampers 15 are arranged radially outward from the center of the base plate. Preferably, the multiple friction dampers 15 are arranged in multiple directions with central angles of 15 to 45 degrees, and the number of friction dampers 15 in each direction is not less than three. In this embodiment, the central angles of each direction are 30 degrees apart.

[0084] Specifically, the friction damper 15 includes a laminated steel plate and friction-type high-strength bolts. The surface of the laminated steel plate is sandblasted, and the friction-type high-strength bolts fix the laminated steel plate. The surface friction coefficient of the laminated steel plate is in the range of 0.4-0.6. Preferably, the friction coefficient is 0.5, thereby improving the energy dissipation efficiency of the friction damper 15.

[0085] The containment structure of this application arranges the friction dampers under the base plate in a radial pattern, which not only makes the energy dissipation capacity of the containment structure similar in all directions, but also ensures that the natural vibration period of the containment structure is similar in all directions. This allows the tuned mass damper formed by the non-Newtonian fluid inside the top cover to play a damping effect in all directions, thereby avoiding the concentration of vibration-induced damage on one side of the containment structure.

[0086] In addition, the support assembly includes multiple vibration isolation supports 16, which are installed below the edge of the base plate and / or at the bottom of the buttress 13. The base plate can be located below the buttress 13 and the annular beam, or it can be located inside the buttress 13 and the annular beam. Preferably, in this embodiment, reference is made to... Figure 1 As shown, the base plate includes a prestressed concrete base plate 17, which is continuous with the prestressed concrete inner wall 14 and located inside the buttress columns 13. Multiple vibration isolation supports 16 are provided at the bottom of the buttress columns 13. Vibration isolation supports are provided around the bottom of the containment structure, which allows the natural vibration period of the containment structure to avoid the natural period of the site, thereby reducing resonance.

[0087] In summary, the prestressed concrete base slab 17, the prestressed concrete inner wall 14, and the prestressed concrete shell 8 are continuous, forming the prestressed concrete inner layer of the containment structure. A steel liner 18 is also provided inside the prestressed concrete inner layer, located at the innermost edge of the containment structure. The prestressed concrete inner layer and the steel liner constitute the inner layer of the entire containment structure, while the double-spherical shell structure, buttresses, and ring beams constitute the outer layer of the entire containment structure.

[0088] In addition, combined Figure 1 , Figure 2 and Figure 4As shown, the containment structure also includes multiple supports 19, which are fixed to the foundation and circumferentially surround the outer perimeter of the sidewalls. Preferably, the supports 19 are reinforced concrete structures, shaped as triangles with a certain thickness. The height of the supports 19 is the same as the height of the second annular beam from bottom to top, the width of the supports 19 is the same as the width of the buttress columns 13, and the length of the supports 19 is selected based on the usable area for the construction of the containment structure within the nuclear power plant.

[0089] This application sets up multiple supports around the main structure of the containment vessel. When vibration causes a large lateral displacement at the bottom of the containment vessel, the reinforced concrete supports around the containment vessel serve as the main components for transmitting lateral forces and resisting lateral displacement. This can effectively limit the horizontal lateral displacement of the containment vessel in all directions. Compared with a multi-layer containment vessel structure, the supports have the advantages of low height, easy construction, and short force transmission path.

[0090] A limiting part 20 is provided on the side of the support body 19 near the side wall. The limiting part 20 is made of viscoelastic material, so that the multiple supports 19 make flexible contact when they collide with the side wall. The limiting parts 20 of the multiple supports 19 are respectively located radially outside the multiple buttress columns 13 in the circumferential direction, and the limiting parts 20 at the same radial position are in clearance fit with the buttress column 13.

[0091] Preferably, the viscoelastic material is a strip of foamed silicone, the length of which is equal to the height of the support 19, the width of which is equal to the width of the support 19, and the thickness of which is 5cm to 10cm. This ensures that the limiting part 20 has sufficient deformation energy dissipation space, and prevents damage to the reinforced concrete support 19 during collisions through flexible contact.

[0092] This application achieves phased energy dissipation by setting a viscoelastic limiting part on the side of the support near the sidewall, which, in combination with the friction damper at the bottom, can dissipate energy in stages. When the displacement response at the bottom of the containment is small, the friction damper is mainly used to dissipate energy. When the displacement response at the bottom of the containment is large enough, energy can be dissipated through both the collision limiting part and the friction damper. The support ensures that the displacement at the bottom of the containment does not exceed a certain limit, and at the same time plays a role in transmitting horizontal loads, seismic forces, and resisting overturning moments. After the limiting part collides with the sidewall, the containment can automatically reset, which is beneficial for structural repair and maintenance after a disaster and reduces the amount of repair work.

[0093] This invention improves upon traditional containment structure designs, resulting in a containment structure that not only possesses high structural stiffness, excellent sealing, low horizontal and vertical seismic response, and strong impact resistance, but also offers advantages such as small footprint, convenient construction, material savings, and low cost. When the containment encounters an earthquake or a large aircraft impact, the non-Newtonian fluid within the dome acts as a tuned liquid damper, reducing the dynamic response of the containment. Bending and shear deformations of the containment under horizontal dynamic forces can be reduced by the energy dissipation of viscous dampers. The vibration isolation supports have relatively low horizontal stiffness; under frequent earthquakes, energy dissipation is primarily achieved through friction dampers to reduce displacement at the bottom of the containment. When the containment encounters a rare large earthquake, the viscoelastic limiting part of the containment and the friction damper's energy dissipation are used to constrain the displacement at the bottom of the containment and achieve a self-resetting effect.

[0094] In summary, it can be seen from the above description that the embodiments of the present invention achieve the following technical effects:

[0095] 1. The top cover of this application has a two-shell structure with an inner shell and an outer shell on the outside, which serves as the first line of defense against the impact of large objects. The space in the hollow part provides space for the deformation of the outer shell, so that when the outer shell is deformed by impact, the inner shell and the prestressed concrete shell are not damaged. Multiple partitions are set in the hollow part at intervals to enhance the overall strength of the two-shell structure and to constrain the deformation range of the outer shell.

[0096] 2. The top cover of this application uses a non-Newtonian fluid as a filler in the two-layer shell structure, which significantly improves the ability of the top of the containment to buffer the impact of large objects and reduces the possibility of secondary disasters caused by the impact. When a large object impacts, the non-Newtonian fluid can share the impact force with the two-layer shell structure, reduce the deformation range of the shell, and evenly distribute the impact force. At the same time, the impact can easily cause a fire. The non-Newtonian fluid inside the two-layer shell structure can reduce the temperature of the shell and has strong fire resistance to prevent the top cover structure of the containment from failing.

[0097] 3. The top cover of this application designs the structure of the fluid space inside the hollow part, and designs the material and parameters of the non-Newtonian fluid inside the fluid space, so that the non-Newtonian fluid inside the top cover forms a tuned liquid damper, which greatly improves the seismic performance of the containment. Under strong vibrations such as earthquakes, the inertia of the liquid itself is used to reduce the horizontal vibration of the upper part of the containment.

[0098] 4. The top cover of this application, by setting anti-corrosion materials on the surfaces of the inner and outer shells, achieves a better sealing effect for the non-Newtonian fluid inside the two shell structures, preventing the non-Newtonian fluid from seeping into the concrete; in addition, when the pressure inside the containment increases sharply, the non-Newtonian fluid itself can act as a counterweight to prevent the top cover of the containment from being ruptured by the internal pressure.

[0099] 5. The containment structure of this application increases the circumferential constraint of the containment structure and enhances its ability to resist internal pressure by setting multiple annular beams on the outer side of the sidewalls; by setting multiple buttresses to bear the weight of the upper two shell structures and non-Newtonian fluids, and connecting the multiple annular beams, the annular beams and buttresses divide the sidewalls of the containment structure into several small grids. When a large object impacts the sidewalls of the containment structure, the annular beams and buttresses can constrain the fracture deformation within the impacted grids to reduce the overall damage to the containment structure and avoid progressive collapse.

[0100] 6. The containment structure of this application can reduce the bending and shear deformation of the containment structure under impact or vibration by consuming energy through multiple viscous dampers arranged on the side wall of the containment structure. The viscous dampers can be tilted to increase energy consumption in both the vertical and radial directions of the containment structure at the same time, thereby reducing the impact of structural deformation on the internal pipes and valves of the containment structure and preventing the containment structure from cracking and causing the leakage of radioactive materials.

[0101] 7. The containment structure of this application arranges the friction dampers under the bottom plate in a radial pattern, which not only makes the energy dissipation capacity of the containment structure similar in all directions, but also ensures that the natural vibration period of the containment structure is similar in all directions. This allows the tuned mass damper formed by the non-Newtonian fluid in the top cover to play a damping effect in all directions, thereby avoiding the concentration of vibration damage on one side of the containment structure. In addition, the vibration isolation bearings are set around the bottom of the containment structure, which allows the natural vibration period of the containment structure to avoid the natural period of the site, thereby reducing resonance.

[0102] 8. This application sets up multiple supports around the main structure of the containment vessel. When vibration causes a large lateral displacement at the bottom of the containment vessel, the reinforced concrete supports around the containment vessel serve as the main components for transmitting lateral forces and resisting lateral displacement. This can effectively limit the horizontal lateral displacement of the containment vessel in all directions. Compared with a multi-layer containment vessel structure, the supports have the advantages of low height, easy construction, and short force transmission path.

[0103] 9. This application achieves phased energy dissipation by setting a viscoelastic limiting part on the side of the support near the side wall, which, in combination with the friction damper at the bottom, can achieve the purpose of phased energy dissipation. When the displacement response at the bottom of the containment is small, the friction energy dissipation mainly relies on the friction damper; when the displacement response at the bottom of the containment is large enough, energy can be dissipated through both the collision limiting part and the friction damper. The support ensures that the displacement at the bottom of the containment will not exceed a certain limit, and at the same time plays the role of transmitting horizontal loads, seismic forces and resisting overturning moments. After the limiting part collides with the side wall, the containment can automatically reset, which is beneficial to structural repair and maintenance after a disaster and reduces the amount of repair work.

[0104] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A top cover for a nuclear power plant containment vessel, having a curved surface structure, characterized in that: It includes an inner shell (1) and an outer shell (2), the inner shell (1) and the outer shell (2) are spaced apart, the outer shell (2) is located radially outside the inner shell (1), a hollow part is formed between the inner shell (1) and the outer shell (2), and the hollow part is filled with a non-Newtonian fluid to improve the impact resistance and seismic performance of the containment vessel; The top cover also includes a plurality of partitions (3), which are located inside the hollow section. The two sides of each partition (3) are connected to the inner shell (1) and the outer shell (2) respectively. The plurality of partitions (3) divide the hollow section into a plurality of spaces. Multiple partitions (3) are spaced apart along the height direction, dividing the space inside the hollow part into 3-5 layers of fluid space (4) along the height direction. Each layer of fluid space (4) contains the non-Newtonian fluid, so that the vibration frequency of the non-Newtonian fluid inside the hollow part is close to the natural frequency of the containment. The non-Newtonian fluid is a shear-thickening fluid, and the critical shear wave velocity of the non-Newtonian fluid is in the range of 10m / s-100m / s.

2. The top cover according to claim 1, characterized in that: The shear thickening fluid comprises polyethylene glycol and silica, wherein the mass fraction of silica is in the range of 60%-65%.

3. The top cover according to claim 1, characterized in that: Both the inner shell (1) and the outer shell (2) have a spherical structure, and at least one of the partitions (3) has an annular structure. The partitions (3) surround the outer circumferential side of the inner shell (1) and divide the hollow part into upper and lower parts.

4. The top cover according to claim 3, characterized in that: The partition (3) includes a first partition (5), a second partition (6) and a third partition (7). The first partition (5), the second partition (6) and the third partition (7) have an annular structure and are arranged in sequence from high to low along the height direction to divide the hollow part into three layers of fluid space (4).

5. The top cover according to claim 1, characterized in that: The surfaces of the multiple partitions (3), the outer wall of the inner shell (1), and the inner wall of the outer shell (2) are all covered with anti-corrosion materials.

6. The top cover according to claim 1, characterized in that: The top cover also includes an inner top layer, which includes a prestressed concrete shell (8) located radially inside the inner shell (1).

7. A nuclear power plant containment vessel, characterized in that: Includes sidewalls and a top cover according to any one of claims 1-6, the sidewalls being located below and connected to the top cover, the sidewalls including a plurality of annular beams (9) and a plurality of viscous dampers (10), the annular beams (9) surrounding the containment in a circumferential direction, the plurality of annular beams (9) being spaced apart in a height direction, and the plurality of viscous dampers (10) being distributed between the plurality of annular beams (9).

8. The nuclear power plant containment vessel according to claim 7, characterized in that: The upper end of the viscous damper (10) is connected to the lower edge of the annular beam (9) above it, and the lower end of the viscous damper (10) is connected to the upper edge of the annular beam (9) below it.

9. The nuclear power plant containment vessel according to claim 8, characterized in that: The lower edge includes a first fixing point (11), and the upper edge includes a second fixing point (12). The first fixing point (11) is located radially inside the containment relative to the second fixing point (12). The upper end of the viscous damper (10) is fixed to the first fixing point (11), and the lower end of the viscous damper (10) is fixed to the second fixing point (12), so that the viscous damper (10) is tilted.

10. The nuclear power plant containment vessel according to claim 9, characterized in that: The viscous material of the viscous damper (10) includes silicone oil, the damping coefficient of the viscous damper (10) is in the range of 0.12-0.18, and the maximum output force is in the range of 1000-2000kN.

11. The nuclear power plant containment vessel according to any one of claims 8-10, characterized in that: Between every two adjacent annular beams (9), a plurality of viscous dampers (10) are arranged at uniform intervals along the circumference of the containment.

12. The nuclear power plant containment vessel according to claim 11, characterized in that: The sidewall also includes an inner wall layer and multiple buttress columns (13). The inner wall layer includes a cylindrical prestressed concrete inner wall (14). The annular beam (9) surrounds the outside of the prestressed concrete inner wall (14) in the circumferential direction. The buttress columns (13) all extend in the height direction and connect multiple annular beams (9). The multiple buttress columns (13) are evenly arranged on the outside of the prestressed concrete inner wall (14) in the circumferential direction.

13. The nuclear power plant containment vessel according to claim 12, characterized in that: Multiple viscous dampers (10) and multiple buttress columns (13) are arranged alternately and at intervals along the outer periphery of the prestressed concrete inner wall (14).

14. The nuclear power plant containment vessel according to claim 12, characterized in that: The containment also includes a base plate and a support assembly, the base plate being located at the bottom of the sidewall, the support assembly connecting the underside of the base plate to the foundation to support the containment, the support assembly including a plurality of friction dampers (15).

15. The nuclear power plant containment vessel according to claim 14, characterized in that: Multiple friction dampers (15) are arranged radially outward from the center of the base plate.

16. The nuclear power plant containment vessel according to claim 15, characterized in that: The friction damper (15) includes a laminated steel plate and a friction-type high-strength bolt, which fixes the laminated steel plate. The surface friction coefficient of the laminated steel plate is in the range of 0.4-0.

6.

17. The nuclear power plant containment vessel according to claim 16, characterized in that: Multiple friction dampers (15) are arranged in multiple directions with a central angle of 15-45 degrees, and the number of friction dampers (15) in each direction is not less than three.

18. The nuclear power plant containment vessel according to any one of claims 15-17, characterized in that: The support assembly also includes a plurality of vibration isolation supports (16), which are installed below the edge of the base plate and / or at the bottom of the buttress column (13).

19. The nuclear power plant containment vessel according to claim 18, characterized in that: The base plate includes a prestressed concrete base plate (17), the prestressed concrete base plate (17), the prestressed concrete inner wall (14) and the prestressed concrete shell (8) are continuous to form the prestressed concrete inner layer of the safety shell.

20. The nuclear power plant containment vessel according to claim 19, characterized in that: The inner side of the prestressed concrete inner layer is also provided with a steel lining (18).

21. The nuclear power plant containment vessel according to claim 12, characterized in that: The containment structure also includes a plurality of supports (19), which are fixed to the foundation and arranged circumferentially around the periphery of the sidewall.

22. The nuclear power plant containment vessel according to claim 21, characterized in that: The support (19) has a limiting part (20) on the side near the side wall. The limiting part (20) is made of viscoelastic material, so that the multiple supports (19) make flexible contact with the side wall when they collide.

23. The nuclear power plant containment vessel according to claim 22, characterized in that: The limiting portions (20) of the plurality of supports (19) are respectively located on the radial outer side of the plurality of buttresses (13) in the circumferential direction, and the limiting portions (20) at the same radial position are in clearance fit with the buttresses (13).

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